Chi Leung "Peter" Wai used the main immigration database to track Hong Kong dissidents in the UK.
He searched it on his days off and sick days, earning money on the side by tracking Hong Kongers who had fled pro-democracy crackdowns for his Chinese contacts. There seems to have been no checks on his access to the database to prevent him doing this.
— Source: BBC News (https://www.bbc.com/news/articles/c0m2wjlkzplo)